An acidic oil-in-water-type emulsified food is a food comprising an aqueous phase component and an oil phase component emulsified in an oil-in-water type emulsion. As examples of typical acidic oil-in-water-type emulsified foods, mayonnaise and salad dressings can be given.
Acidic oil-in-water-type emulsified food may change the flavor, deteriorate, or discolor as a result of oxidation of the components during storage. In order to prevent oxidation, a food additive containing a chemical compound such as EDTA Ca.2Na is often added (Charlotte Jacobsen et al., “Lipid Oxidation in Fish Oil Enriched Mayonnaise, Calcium Disodium Ethylenediaminetetraacetate, but Not Gallic Acid, Strongly Inhibited Oxidative Deterioration”, Journal of Agricultural and Food Chemistry, American Chemical Society, 49, 1009-1019, 2001; Charlotte Jacobsen et al., “The Effect of Metal Chelators on Lipid Oxidation in Milk and Mayonnaise”, 95th AOCS Annual Meeting & Expo, American Oil Chemists' Society, 83-84, 2004).
However, the effects of chemical compounds used as food additives on human bodies are recognized as a problem in recent years. Moreover, consumers have a tendency of avoiding the use of artificial food additives in recent years. For this reason, avoiding the use of chemical compounds in foods as much as possible is desired.